/* -*-mode:java; c-basic-offset:2; -*- */
/*
Copyright (c) 2000,2001,2002,2003 ymnk, JCraft,Inc. All rights reserved.
 
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
 
  1. Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
 
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the distribution.
 
  3. The names of the authors may not be used to endorse or promote products
     derived from this software without specific prior written permission.
 
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * This program is based on zlib-1.1.3, so all credit should go authors
 * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
 * and contributors of zlib.
 */

package com.jcraft.jzlib;
// #sijapp cond.if modules_ZLIB is "true" #
final class InfBlocks {
    private static final int MANY = 1440;
    
    // And'ing with mask[n] masks the lower n bits
    private static final int[] inflate_mask = {
        0x00000000, 0x00000001, 0x00000003, 0x00000007, 0x0000000f,
        0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 0x000001ff,
        0x000003ff, 0x000007ff, 0x00000fff, 0x00001fff, 0x00003fff,
        0x00007fff, 0x0000ffff
    };
    
    // Table for deflate from PKZIP's appnote.txt.
    private static final int[] border = { // Order of the bit length code lengths
        16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
    };
    
    static final private int Z_OK=0;
    static final private int Z_STREAM_END=1;
    static final private int Z_BUF_ERROR=-5;
    
    static final private int TYPE=0;  // get type bits (3, including end bit)
    static final private int LENS=1;  // get lengths for stored
    static final private int STORED=2;// processing stored block
    static final private int TABLE=3; // get table lengths
    static final private int BTREE=4; // get bit lengths tree for a dynamic block
    static final private int DTREE=5; // get length, distance trees for a dynamic block
    static final private int CODES=6; // processing fixed or dynamic block
    static final private int DRY=7;   // output remaining window bytes
    static final private int DONE=8;  // finished last block, done
    static final private int BAD=9;   // ot a data error--stuck here
    
    private int mode;            // current inflate_block mode
    
    private int left;            // if STORED, bytes left to copy
    
    private int table;           // table lengths (14 bits)
    private int index;           // index into blens (or border)
    private int[] blens;         // bit lengths of codes
    private int[] bb = new int[1]; // bit length tree depth
    private int[] tb = new int[1]; // bit length decoding tree
    
    private InfCodes codes;      // if CODES, current state
    
    private boolean last;            // true if this block is the last block
    
    // mode independent information
    int bitk;            // bits in bit buffer
    int bitb;            // bit buffer
    int[] hufts;         // single malloc for tree space
    byte[] window;       // sliding window
    int end;             // one byte after sliding window
    int read;            // window read pointer
    int write;           // window write pointer
    private boolean checkfn;      // check function
    private long adlerHash;          // check on output
    
    private InfTree inftree = new InfTree();
    private ZBuffers z;
    
    InfBlocks(ZBuffers z, boolean checkfn, int w) {
        hufts = new int[MANY * 3];
        window = new byte[w];
        end = w;
        this.checkfn = checkfn;
        mode = TYPE;
        this.z = z;
        codes = new InfCodes(z);
        reset();
    }
    
    long getAdlerHash() {
        return adlerHash;
    }
    final void reset() {
        if (CODES == mode) {
            codes.free();
        }
        mode = TYPE;
        bitk = 0;
        bitb = 0;
        read = write = 0;
        
        if (checkfn) {
            adlerHash = Adler32.adler32(0L, null, 0, 0);
        }
    }
    
    int result = Z_OK;
    void proc() throws ZError {
        int t;              // temporary storage
        int b = bitb;            // bit buffer
        int k = bitk;            // bits in bit buffer
        int p = z.next_in_index; // input data pointer
        int n = z.avail_in;      // bytes available there
        int q = write;                        // output window write pointer
        int m = (q < read ? read - q - 1 : end - q); // bytes to end of window or read pointer
        byte[] z_next_in = z.next_in;
        
        // process input based on current state
        while (true) {
            switch (mode) {
                case TYPE:
                    while (k < 3) {
                        if (n != 0) {
                            result = Z_OK;
                        } else {
                            bitb = b;
                            bitk = k;
                            z.avail_in = n;
                            z.next_in_index = p;
                            write = q;
                            inflate_flush();
                            return;
                        }
                        n--;
                        b |= (z_next_in[p++] & 0xff) << k;
                        k += 8;
                    }
                    t = (int)(b & 7);
                    last = (t & 1) == 1;
                    
                    switch (t >>> 1) {
                        case 0:                         // stored
                        {
                            b >>>= (3);
                            k -= (3);
                        }
                        t = k & 7;                    // go to byte boundary
                        
                        {b>>>=(t);k-=(t);}
                        mode = LENS;                  // get length of stored block
                        break;
                        case 1: {                       // fixed
                            int bl = InfTree.fixed_bl; //literal desired/actual bit depth
                            int bd = InfTree.fixed_bd; //distance desired/actual bit depth
                            int[] tl = InfTree.fixed_tl; //literal/length tree result
                            int[] td = InfTree.fixed_td; //distance tree result
                            codes.init(bl, bd, tl, 0, td, 0);
                            {b>>>=(3);k-=(3);}
                            mode = CODES;
                        }
                        break;

                        case 2:                         // dynamic
                            {b>>>=(3);k-=(3);}
                            mode = TABLE;
                            break;

                        case 3:                         // illegal
                            throw new ZError(ZError.Z_DATA_ERROR);
                    }
                    break;

                case LENS:
                    while (k < 32) {
                        if (n != 0) {
                            result = Z_OK;
                        } else {
                            bitb=b; bitk=k;
                            z.avail_in=n;
                            z.next_in_index=p;
                            write=q;
                            inflate_flush();
                            return;
                        }
                        n--;
                        b |= (z_next_in[p++] & 0xff) << k;
                        k += 8;
                    }
                    
                    if ((((~b) >>> 16) & 0xffff) != (b & 0xffff)) {
                        ZStream.setMsg("invalid stored block lengths");
                        throw new ZError(ZError.Z_DATA_ERROR);
                    }
                    left = (b & 0xffff);
                    b = k = 0;                       // dump bits
                    mode = left!=0 ? STORED : (last ? DRY : TYPE);
                    break;

                case STORED:
                    if (n == 0) {
                        bitb = b;
                        bitk = k;
                        z.avail_in = n;
                        z.next_in_index = p;
                        write = q;
                        inflate_flush();
                        return;
                    }
                    
                    if (m == 0) {
                        if (q == end && read != 0) {
                            q = 0;
                            m = (q < read ? read - q - 1 : end - q);
                        }
                        if (m == 0) {
                            write = q;
                            inflate_flush();
                            q = write;
                            m =(q < read ? read - q - 1 : end - q);
                            if (q == end && read != 0) {
                                q = 0;
                                m = (q < read ? read - q - 1 : end - q);
                            }
                            if (m == 0) {
                                bitb=b; bitk=k;
                                z.avail_in=n;
                                z.next_in_index=p;
                                write=q;
                                inflate_flush();
                                return;
                            }
                        }
                    }
                    result = Z_OK;
                    
                    t = left;
                    if(t>n) t = n;
                    if(t>m) t = m;
                    System.arraycopy(z.next_in, p, window, q, t);
                    p += t;  n -= t;
                    q += t;  m -= t;
                    if ((left -= t) != 0)
                        break;
                    mode = last ? DRY : TYPE;
                    break;
                    
                case TABLE:
                    while (k < 14) {
                        if (n != 0) {
                            result = Z_OK;
                        } else {
                            bitb = b;
                            bitk = k;
                            z.avail_in = n;
                            z.next_in_index = p;
                            write = q;
                            inflate_flush();
                            return;
                        }
                        n--;
                        b |= (z_next_in[p++] & 0xff) << k;
                        k += 8;
                    }
                    
                    table = t = (b & 0x3fff);
                    if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) {
                        ZStream.setMsg("too many length or distance symbols");
                        throw new ZError(ZError.Z_DATA_ERROR);
                    }
                    t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
                    if ((null == blens) || (blens.length < t)) {
                        blens=new int[t];
                    } else{
                        for(int i=0; i<t; i++){blens[i]=0;}
                    }
                    
                    {b>>>=(14);k-=(14);}
                    
                    index = 0;
                    mode = BTREE;

                case BTREE:
                    while (index < 4 + (table >>> 10)) {
                        while (k < 3) {
                            if (n != 0) {
                                result = Z_OK;
                            } else {
                                bitb = b;
                                bitk = k;
                                z.avail_in = n;
                                z.next_in_index = p;
                                write = q;
                                inflate_flush();
                                return;
                            }
                            n--;
                            b |= (z_next_in[p++] & 0xff) << k;
                            k += 8;
                        }
                        
                        blens[border[index++]] = b & 7;
                        
                        {b >>>= (3); k -= (3);}
                    }
                    
                    while  (index < 19) {
                        blens[border[index++]] = 0;
                    }
                    
                    bb[0] = 7;
                    inftree.inflate_trees_bits(blens, bb, tb, hufts);

                    index = 0;
                    mode = DTREE;
                    
                case DTREE:
                    while (true) {
                        t = table;
                        if(!(index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))){
                            break;
                        }
                        
                        int[] h;
                        int i, j, c;
                        
                        t = bb[0];
                        
                        while (k < t) {
                            if (n != 0) {
                                result = Z_OK;
                            } else {
                                bitb = b; bitk = k;
                                z.avail_in = n;
                                z.next_in_index = p;
                                write = q;
                                inflate_flush();
                                return;
                            }
                            n--;
                            b |= (z_next_in[p++] & 0xff) << k;
                            k += 8;
                        }
                        
                        if (tb[0] == -1) {
                            //System.err.println("null...");
                        }
                        
                        t = hufts[(tb[0] + (b&inflate_mask[t])) * 3 + 1];
                        c = hufts[(tb[0] + (b&inflate_mask[t])) * 3 + 2];
                        
                        if (c < 16) {
                            b >>>= t;
                            k -= t;
                            blens[index++] = c;
                        } else { // c == 16..18
                            i = c == 18 ? 7 : c - 14;
                            j = c == 18 ? 11 : 3;
                            
                            while (k < (t + i)) {
                                if (n != 0) {
                                    result = Z_OK;
                                } else {
                                    bitb = b;
                                    bitk = k;
                                    z.avail_in = n;
                                    z.next_in_index = p;
                                    write = q;
                                    inflate_flush();
                                    return;
                                }
                                n--;
                                b |= (z_next_in[p++] & 0xff) << k;
                                k += 8;
                            }
                            
                            b >>>= t;
                            k -= t;
                            
                            j += (b & inflate_mask[i]);
                            
                            b >>>= i;
                            k -= i;
                            
                            i = index;
                            t = table;
                            if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
                                    (c == 16 && i < 1)) {
                                ZStream.setMsg("invalid bit length repeat");
                                throw new ZError(ZError.Z_DATA_ERROR);
                            }
                            
                            c = (c == 16) ? blens[i - 1] : 0;
                            do {
                                blens[i++] = c;
                            } while (--j != 0);
                            index = i;
                        }
                    }
                    
                    tb[0]=-1;
                    {
                        int[] bl = new int[1];
                        int[] bd = new int[1];
                        int[] tl = new int[1];
                        int[] td = new int[1];
                        bl[0] = 9;         // must be <= 9 for lookahead assumptions
                        bd[0] = 6;         // must be <= 9 for lookahead assumptions
                        
                        t = table;
                        inftree.inflate_trees_dynamic(257 + (t & 0x1f),
                                1 + ((t >> 5) & 0x1f),
                                blens, bl, bd, tl, td, hufts);
                        t = Z_OK;
                        codes.init(bl[0], bd[0], hufts, tl[0], hufts, td[0]);
                    }
                    mode = CODES;
                    
                case CODES:
                    bitb = b;
                    bitk = k;
                    z.avail_in = n;
                    z.next_in_index = p;
                    write = q;
                    
                    codes.proc(this);
                    if (Z_STREAM_END != result) {
                        inflate_flush();
                        return;
                    }
                    result = Z_OK;
                    codes.free();
                    
                    p = z.next_in_index;
                    n = z.avail_in;
                    b = bitb;
                    k = bitk;
                    q = write;
                    m = (q < read ? read - q - 1 : end - q);
                    
                    mode = last ? DRY : TYPE;
                    break;
                    
                case DRY:
                    write = q;
                    inflate_flush();
                    q = write;
                    m = (q < read ? read - q - 1 : end - q);
                    if (read != write) {
                        bitb = b;
                        bitk = k;
                        z.avail_in = n;
                        z.next_in_index = p;
                        write = q;
                        inflate_flush();
                        return;
                    }
                    mode = DONE;
                    result = Z_STREAM_END;
                    bitb = b;
                    bitk = k;
                    z.avail_in = n;
                    z.next_in_index = p;
                    write = q;
                    inflate_flush();
                    
                case DONE:
                    result = Z_STREAM_END;
                    return;
                    
                case BAD:
                    throw new ZError(ZError.Z_DATA_ERROR);
                    
                default:
                    throw new ZError(ZError.Z_STREAM_ERROR);
            }
        }
    }
    
    final void free() {
        reset();
        window = null;
        hufts = null;
        //ZFREE(z, s);
    }
    
    /**
     * @unused
     */
    private void set_dictionary(byte[] d, int start, int n) {
        System.arraycopy(d, start, window, 0, n);
        read = write = n;
    }
    
    // copy as much as possible from the sliding window to the output area
    void inflate_flush() {
        // local copies of source and destination pointers
        int p = z.next_out_index;
        int q = read;
        
        // compute number of bytes to copy as far as end of window
        int n = ((q <= write ? write : end) - q);
        if (n > z.avail_out) {
            n = z.avail_out;
        }
        if ((0 != n) && (Z_BUF_ERROR == result)) {
            result = Z_OK;
        }
        
        // update counters
        z.avail_out -= n;
        
        // update check information
        if (checkfn) {
            adlerHash = Adler32.adler32(adlerHash, window, q, n);
        }
        
        // copy as far as end of window
        System.arraycopy(window, q, z.next_out, p, n);
        p += n;
        q += n;
        
        // see if more to copy at beginning of window
        if (q == end) {
            // wrap pointers
            q = 0;
            if (write == end)
                write = 0;
            
            // compute bytes to copy
            n = write - q;
            if (n > z.avail_out) {
                n = z.avail_out;
            }
            if ((0 != n) && (Z_BUF_ERROR == result)) {
                result = Z_OK;
            }
            
            // update counters
            z.avail_out -= n;
            
            // update check information
            if (checkfn) {
                adlerHash = Adler32.adler32(adlerHash, window, q, n);
            }
            
            // copy
            System.arraycopy(window, q, z.next_out, p, n);
            p += n;
            q += n;
        }
        
        // update pointers
        z.next_out_index = p;
        read = q;
    }
}
// #sijapp cond.end #
